Installations for the treatment, in gaseous medium, of a strip product

ABSTRACT

The band of product moves through a treatment zone facing blower caissons. The blower walls of the caissons include apertures distributed according to a succession of contours and along middle lines joining the two large sides of each contour, transverse passages being arranged between each contour. The small side of the contour is greater than half the pitch by which the groups of blower apertures are distributed. The sum of the sections of the outlet passages is greater than the sum of the sections of the blower apertures and inlet apertures.

[4 Dec. El, 1973 United States Patent [1 1 Marchal 54 INSTALLATIONS FORTHE TREATMENT, 3,199,224 8/1965 34/156 IN GASEOUS MEDIUM, OF A STRIP$638,330 2/1972 PRODUCT FOREIGN PATENTS OR APPLICATIONS Inventor:

Stout....

. 668,741 3/1952 Sweden..........

Paul-Henri Marchal,

Neuilly-sur-Seine, France [73] Assignee: Air-lndustrie, Courbevoie,France 'f' Dority Assistant ExammerLarry I. Schwartz Filed: July 23Attorney-Larson, Taylor & Hinds [21] Appl. No.: 165,494

[57] ABSTRACT The band of product moves through a treatment zone [30]Foreign Application Priority Data Aug. 10, 1970France...............................

facing blower caissons. The blower walls of the caisof the contour isgreater than half the'pitch by which the groups of blower apertures aredistributed. The

References Cited UNITED STATES PATENTS 8/ 1958 l2/l96l sum of thesections of the outlet passages is greater than the sum of the sectionsof the blower apertures and inlet apertures.

2,848,820 Wallin et al. 34/23 3,012,335 Allander et al. 34/155 3,048,3838/1962 Champlin.............................. 34/156 9 Claims, 3 DrawingFigures PATENTEDIJEC n I975 SHEET 1 OF 3 PATENIEUDEC H 1975 3,777,408

SHEET 3 BF 3 INSTALLATIONS FOR THE TREATMENT, IN GASEOUS MEDIUM, OF ASTRIP PRODUCT The invention relates to installations enabling thecarrying out, in a gaseous medium, on a product in a band, of treatmentsof various natures, especially chemical, physical, or physical chemicaltreatments.

The invention relates more particularly, because it is in this case thatits application seems to offer the most advantage, but not exclusively,among these installations, to those for the drying of a product in aband, especially in a flexible, deformable and fragile band.

It has already been proposed to include in such an installation atreatment zone in which the band or strip product is moved, thistreatment zone being situated facing one or several blower caissonssupplied by gas, called treatment gas.

Each blower caisson has, on the side of the treatment zone, blower wallscomprising,

blower apertures to ensure the maintenance and to contribute to thetreatment of the band of product,

inlet apertures to complete the treatment of the band of product,

and outlet passages to remove the gas blown into the treatment zone bythe abovesaid blower and inlet apertures.

In an installation of this type, the problems to be resolved consistprincipally,

of ensuring stable maintenance of the band of product in the treatmentzone,

to avoid jets of gas emerging from the blower apertures causing marks onthe band of product,

to ensure treatment, especially drying, as efficiently as possible.

It is a particular object of the invention to provide an installationwhich enables, stable maintenance of the band of product in thetreatment zone to be ensured,

to avoid jets of gas emerging from the blower apertures causing marks onthe band of product,

and to ensure efficient treatment, especially of dry- It is a furtherobject of the invention to provide an installation which lends itselfparticularly well to treatments, especially drying, to be effected on aband of flexible, deformable and fragile product.

It is a further object of the invention to provide an installation ofwhich the bulk, especially the length, can be reduced.

The installation according to the invention is characterized by the factthat,

the blower apertures form groups which have distributed along thedirection of movement of the band of product and which each comprise, onone hand, blower apertures arranged along a contour of rectangularshape, of which the large side is perpendicular to the direction ofmovement of the band of product and has a dimension at least equal tothe maximum width of the band of product, and, on the other hand, bloweraper-, tures arranged along median lines regularly spaced and rejoiningthe two large sides of the abovesaid contour,

the inlet apertures are arranged inside the contour,

and extraction passages are arranged between each contour,

the section of each inlet orifice being greater than the section of eachblower orifice,

the small side of the contour being greater than half the pitch alongwhich are distributed the groups of blower apertures,

the sum of the sections of the outlet passages being greater than thesum of the sections of the blower and inlet apertures.

It will be appreciated then that, due to this distribution and thisarrangement of the blower apertures, of the inlet apertures and of theoutlet passages, there is ensured for the band of product a stablemaintenance in the treatment zone, that jets of gas emerging from theblower apertures causing marks on the band of products are avoided, andthat a treatment, especially drying, as efficient as possible isensured.

It will also be appreciated that, in the same installation, it ispossible to treat bands of product of different widths.

The invention consists, apart from this main feature, of certain otherfeatures which are preferably used at same time and which will be moreexplicitly considered in the further description which follows,illustrated by the accompanying drawings, this further description andthese drawings relating to the preferred embodiments of the inventionand not being of course of any limiting character.

FIG. 1, of these drawings, is'a diagrammatic view in perspective of oneembodiment of an installation constructed according to a firstembodiment of the invention.

FIG. 2 is a partial view in perspective of an installation constructedaccording to a second embodiment of the invention.

FIG. 3 is a partial view in perspective of a third em- I bodiment of aninstallation constructed according to the invention.

In FIG. 1, there is shown an installation for the drying of a band ofproduct 1 moving horizontally in a treatment zone 2 from one side to theother ofvwhich occur arranged several blower caissons 3.

Each blower caisson 3 has, on the side of the treatment zone 2, a blowerwall 4 comprising,

blower apertures 5 to ensure the maintenance and to contribute to thetreatment of the band of product 1,

inlet apertures 7 to complete the treatment of the band of product 1,

and, outlet passages 8 to remove the gas blown into the treatment zone 2by the abovesaid blower apertures 5 and inlet 7 apertures.

The blower apertures 5 form groups 6 which are distributed along thedirection of movement of the band of product 1 and which comprise each,

on one hand, blower apertures 5 arranged along a contour L ofrectangular shape, of which the large side is perpendicular to thedirection of movement XX of the band of product 1 and has a dimension atleast equal to the maximal width of the band of product 1,

and, on the other hand, blower apertures 5 arranged along median lines Mspaced regularly and rejoining the two large sides of the abovesaidcontour L.

The inlet apertures 7 are arranged inside the contour And the outletpassages 8 are arranged between each contour L.

The section of each inlet aperture 7 is greater than the section of eachblower aperture 5.

The small side of the contour L is greater than half of the pitch Palong which are distributed the groups 6 of blower apertures 5.

The sum of the sections of the outlet passages 8 is greater than the sumof the sections of the blower and inlet 7 apertures.

Preferably, the median lines M of a same group 6 of blower apertures 5are parallel between themselves.

These median lines M may be parallel to the direction of movement XX ofthe band of product 1 (FIG. I), or preferably inclined with respect tothis direction of movement XX (FIGS. 2 and 3).

As shown in these FIGS. 2 and 3, the median lines M are inclined withrespect to the direction of movement XX of the band of product 1, thevalue of this inclination a being less than or equal to 45.

The small sides of contour L are then advantageously parallel to themedian lines M, the said contour L having the shape of aparallelogramme.

Under these conditions, all the groups 6 can have median lines Mparallel between themselves from one group to the other (FIG. 2).

However, the groups 6 can be distributed in series, the groups of a sameseries having median lines M parallel, two successive series of groups 6having median lines M inclined in symmetrical manner with respect to thedirection of movement XX of the band of product 1 (FIG. 3).

When all groups 6 have median lines M inclined with respect to thedirection of movement XX of the band of product 1 and parallel betweenthemselves, these median lines M can be displaced from one group to thefollowing group so that there are presented in identical manner in thecontour L all the n groups, n being greater than unity (FIG. 2).

With regard to the embodiment illustrated in this FIG. 2, theperiodicity with which an identical arrangement recurs, of the medianlines M in the contour L, is four.

As regards the inlet aperture 7, it should be specified that they arepreferably arranged, inside the contour L, so as to be aligned, in thetransverse direction along parallels to the large sides of the contourL,

and, in the longitudinal direction, along parallels to the median linesM.

As for the extraction passages 8, they may be constituted by recoverychimneys aligned along a direction perpendicular to the direction ofmovement XX of the band of product 1 (FIG. 2), or by slots perpendicularto the direction of movement XX of the band of product 1 (FIG. 1 and 3).

In the case where the outlet passages 8 are constituted by recoverychimneys, it is advantageous to arrange the said recovery chimneys atregular intervals, equal to the intervals of the median lines M, and byfollowing a displacement, from one group to the following one, identicalto the displacement of the abovesaid median lines M (FIG. 2).

In the case where the outlet passages 8 are constituted by slots, it isadvantageous to give the said slots a length greater than the dimensionof the large side of the contour L (FIG. 3).

As regards the blower apertures 5 distributed, for a group 6, along acontour L and median lines M, they may be constituted by circular holesof 3 to 5 mm diameter spaced regularly along a pitch of 5 to 10 mm.

However these blower apertures 5 could be constituted by elongated holesin the direction of the contour L or in the direction of the medianlines M.

As regards the inlet apertures 7, they can be also constituted bycircular holes of 5 to 15 mm diameters spaced regularly.

However these inlet apertures 7 could also be constituted by elongatedholes extending perpendicularly to the direction of movement XX of theband of product 1.

' Referring to FIG. 2, in which the extraction passages 8 areconstituted by chimneys, it may be indicated by way of example that,

the section of each inlet aperture 7 is two to three times greater thanthe section of each blower aperture the small side of the contour L isequal to 62 percent of the value of the pitch P along which aredistributed the groups 6 of blower apertures 5,

and the sum of the sections of the outlet passages 8 is greater by 94percent than the sum of the sections of the blower 5 and inlet 7apertures.

Referring to FIG. 3, in which the outlet passages 8 are constituted byslots, it may be indicated by way of example that,

the section of each inlet aperture 7 is two to three times greater thanthe section of each blower aperture the small side of the contour L isequal to 77 percent of the value or the pitch P along which aredistributed the groups 6 of blower apertures 5,

and the sum of the sections of the extraction passages 8 is greater by44 percent than the sum of the sections of the blower 5 and inlet 7apertures. I

The operation of the installation which has just been described is thenas follows The jets of gas delivered by the inlet apertures 7 and theblower apertures 5 distributed along the median lines M strike the bandof product 1, and there are then produced between the gas jets and thisband terminal exchanges by force to convention.

The gas tends to escape towards the extraction passages 8 which areclosest and it encounters on its path the whole of the jets of gasdelivered by the blower apertures 5 distributed along the large sides ofthe contours L of the groups 6.

These jets of gas being very close to one another,

form a closed gaseous wall and the gas delivered by the inlet aperture 7and the blower apertures 5 distributed along the median lines M causesthe said walls to flare outwardly.

It will then be understood that the difference in static pressure whichthereby results is (at least to first approximation) inverselyproportional to the distance which separates the band of product 1 fromthe blower walls 4 considered.

The average pressure which exists in the space situated between the bandof product 1 and the zones of the blower walls 4 which are comprisedbetween the group 6 will also tend to increase if the abovesaid bandapproaches the blower wall considered under the action of an externalforce (for example under the action of the weight of the damagedproduct).

Finally, the band of product 1 occurs therefore subject to staticpressures on both sides of its two surfaces, and the vectorial sum ofthese static pressures is opposed to any movement of approach to oneanother of the opposite blower walls 4.

The position of the band of product 1 is hence automatically ensured inthe treatment zone 2, as well in the case envisaged'by way of example,where this band is moved horizontally, as in the case where this band ismoved vertically.

It should be pointed out that the jets of gas delivered by the blowerapertures 5 distributed along the small sides of the contour L enablethe delivery of a preferential escape of the gas in the transversedirection, which transverse escape would have a tendency to reduce theeffect of the jets of gas delivered by the blower apertures 5distributed over the large sides of the contour L.

Moreover, it will be understood that in the case of a band of product 1,very flexible, hence deformable and fragile, the partitioning of thecontour L by the median lines M enables the obtaining of a plurality ofelemental lifting zones capable of reacting independently of one anotherto local pulling of the band of product 1.

Finally and whatever the embodiment, there is obtained an installationfor the drying of a strip product which has a certain number ofadvantages among which may be summarized the following stable holding ofthe band of product in the treatment zone,

- absence of marking on the strip product,

homogeneous treatment over the whole surface of the strip,

possibility of preceding with treatment on fragile bands and of slightrigidity,

possibility of treating, in a same installation, strip products ofdifferent widths.

I claim 1. In an installation for the treatment, in a gaseous medium, ofa band of product moving in a treatment zone situated between blowercaissons supplied with treatment gas, the caissons having, on each sideof the treatment zone, blower walls comprising groups of inlet andblower apertures for connection to a gas supply means and groups ofoutlet passages for exhausting gaseous medium from the treatment zone,these groups being arranged alternately with respect to the direction ofmovement of the band, the improvements comprising means in each group ofapertures for forming a closed gaesous wall extending in a closedcontour of ertures to impose a degree of confinement on the gaseousmedium inside the contour, said means including a plurality of closelyspaced, relatively small blower apertures arranged along a contour orrectangular shape, of which the larger side is perpendicular to thedirection of movement of the band and is at least equal to the width ofthis band, said inlet apertures being relatively large and arrangedinside said contour, the section of each inlet aperture being at leasttwice as great as the section of each blower aperture, and additionalblower apertures equally arranged and closely spaced along median linesregularly spaced and joining the two large sides of the said contour,the small side of each contour being greater than half the pitch alongwhich the groups of inlet and blower apertures are distributed, and thesum of the sections of the outlet passages being greater than the sum ofthe sections of the inlet and blower apertures.

2. Installation according to claim 1, wherein the median lines of a samegroup of blower apertures are parallel between themselves.

3. Installation according to claim 2, wherein the median lines areparallel to the direction of movement of the band of product.

4. Installation according to claim 2, wherein the median lines areinclined with respect to the direction of movement to the band ofproduct.

5. Installation according to claim 4, wherein the angle of inclinationof the median lines with respect to the direction of movement of band ofproduct is less than 45.

6. Installation according to claim 4, wherein the small sides of thecontour are parallel to the median lines.

7. Installation according to claim 4, wherein all the groups of blowerapertures have median lines parallel between themselves from one groupto the other.

8. Installation according to claim 4, wherein the groups of blowerapertures are distributed in series, the groups of a same series havingparallel median lines, whilst two successive series of groups havemedian lines inclined symmetrically with respect to the direction ofmovement of the band of product.

9. Installation according to claim 3, wherein the median lines arestaggered from one group to the other, such they have in identicalmanner in the contour all the n groups, n being equal to or greater thanunity.

1. In an installation for the treatment, in a gaseous medium, of a bandof product moving in a treatment zone situated between blower caissonssupplied with treatment gas, the caissons having, on each side of thetreatment zone, blower walls comprising groups of inlet and blowerapertures for connection to a gas supply means and groups of outletpassages for exhausting gaseous medium from the treatment zone, thesegroups being arranged alternately with respect to the direction ofmovement of the band, the improvements comprising means in each group ofapertures for forming a closed gaesous wall extending in a closedcontour of rectangular configuration and surrounding the Inlet aperturesto impose a degree of confinement on the gaseous medium inside thecontour, said means including a plurality of closely spaced, relativelysmall blower apertures arranged along a contour or rectangular shape, ofwhich the larger side is perpendicular to the direction of movement ofthe band and is at least equal to the width of this band, said inletapertures being relatively large and arranged inside said contour, thesection of each inlet aperture being at least twice as great as thesection of each blower aperture, and additional blower apertures equallyarranged and closely spaced along median lines regularly spaced andjoining the two large sides of the said contour, the small side of eachcontour being greater than half the pitch along which the groups ofinlet and blower apertures are distributed, and the sum of the sectionsof the outlet passages being greater than the sum of the sections of theinlet and blower apertures.
 2. Installation according to claim 1,wherein the median lines of a same group of blower apertures areparallel between themselves.
 3. Installation according to claim 2,wherein the median lines are parallel to the direction of movement ofthe band of product.
 4. Installation according to claim 2, wherein themedian lines are inclined with respect to the direction of movement tothe band of product.
 5. Installation according to claim 4, wherein theangle of inclination of the median lines with respect to the directionof movement of band of product is less than 45*.
 6. Installationaccording to claim 4, wherein the small sides of the contour areparallel to the median lines.
 7. Installation according to claim 4,wherein all the groups of blower apertures have median lines parallelbetween themselves from one group to the other.
 8. Installationaccording to claim 4, wherein the groups of blower apertures aredistributed in series, the groups of a same series having parallelmedian lines, whilst two successive series of groups have median linesinclined symmetrically with respect to the direction of movement of theband of product.
 9. Installation according to claim 3, wherein themedian lines are staggered from one group to the other, such they havein identical manner in the contour all the n groups, n being equal to orgreater than unity.